[New approaches to environmental epidemiology].

The collaboration between epidemiology and the laboratory (molecular investigations) has been proposed to face some of the limitations of epidemiological studies, in particular errors in exposure identification and assessment for environmental exposures. Molecular epidemiology has some advantages: changes in biomarkers appear early in the disease process, i.e. it is not necessary to wait for decades for the onset of a chronic disease in populations exposed to environmental contaminants; biomarkers allow a better quantification of <>, and draw our attention to the role of the environment and early damage rather than individual susceptibility. In the mean time limitations of biomarkers need to be addressed, in particular the lack of validation, the limited reproducibility of several biomarkers, and the fact that measurements are expensive and cumbersome.